1. Field of the Invention
The present invention relates to improvements to inflatable reservoirs for containing liquids, and more especially to inflatable swimming pools which are made from a flexible and fluid tight material; the invention also relates to a method for filling such a reservoir.
2. Description of the Prior Art
Numerous examples of liquid reservoirs are already known, more especially swimming pools, comprising a peripheral tube inflated by a pressurized gas (generally air), and surrounding a central region intended to contain the liquid (water in the case of swimming pools). Although such reservoirs are particularly advantageous from numerous points of view (low cost, ease of setting up, low weight when empty, ease of storing once deflated, etc . . . ), they have however an important disadvantage which is that the gas tightness of the peripheral tube is not perfect and this tube deflates gradually (leaks due to the permeability of the material and leaks at the filling valve). The imperfectly inflated tube risks collapsing under the action of the thrust of the liquid, with overspilling of the liquid. It is then necessary to regularly check the inflation condition of the peripheral tube and to reinflate it periodically
To avoid having to carry out such checks and reinflation at too close intervals, it has already been proposed to cause the inner volume of the peripheral tube to communicate with the liquid filling space of the reservoir, so that a small amount of liquid penetrates into the bottom of the tube. The pressure of the inflation gas of the tube is therefore determined by the weight of the water column separating the levels of the liquid reigning in the tube and in the central region of the reservoir, and any gas leak is automatically compensated for a proportional rise of the level of the liquid in the tube. The inflation pressure of the tube, without being strictly constant, remains however sufficiently stable over a long period of time to allow the checks to be advantageously spaced apart. One example of such a construction is given in the U.S. Pat. No. 2,529,872 (VH Hasselquist). However, the proposed arrangement is extremely complex and requires numerous cut outs and extensive lengths of welding of the flexible material forming the reservoir. Furthermore, the lateral thrust exerted by the liquid is compensated for by an inner peripheral reinforcement which is extremely annoying for the users.
The aim of the invention is essentially to provide an inflatable reservoir, more especially a swimming pool, which combines the respective advantages of the prior reservoirs of the two above mentioned types, but which does not have the respective drawbacks.